Described is a combination of a closing cap (1') for a container (2) and a neck (201) of the container (2), wherein the cap (1') comprises a lateral wall (3) extending about an axis (Z) and a transversal wall (4) positioned at an end of the lateral wall (3), a separation line (5') of the lateral wall (3) defining a retaining ring (301'), configured to remain anchored to the neck (201) and a closing element (302) to open or close the container (2). The separation line (5') extends about the axis (Z) and is circumferentially interrupted so as to leave the retaining ring (301) and the closing element (302) joined together. The retaining ring (301') comprises a retaining portion (303), configured to engage internally with a locking ring (202) of the neck (201), the latter projecting from an outer surface of the neck (201) and extending in a direction parallel to the axis (Z) between an upper end (202c) and a lower end (202b). The retaining ring (301') comprises a joining portion (305) which allows the retaining ring (301') to be joined to the closing element (302), a first connecting band (306) and a second connecting band (307), which connect the joining portion (305) to the retaining portion (303), and a tab (308) positioned between the first connecting band (306) and the second connecting band (307). The connecting bands (306; 307) are made by an incision line (7') which comprises a first lateral stretch (702') and a second lateral stretch (703') wherein the first lateral stretch (702') and the second lateral stretch (703'), when the closing element (302) is in a closed condition, are arranged in such a way that when the closing element (302) is in an open condition and the connecting bands (306, 307) keep the closing element (302) connected to the retaining ring (301'), the tab (308) can rest on the neck (201) beyond the upper end (202c) of the locking ring (202) towards the dispensing opening (203).